Chia-Ching Liaw

Frajunolides E-K, briarane diterpenes from Junceella fragilis.

Chemical investigation of the gorgonian octocoral Junceella fragilis, collected in Taiwan, resulted in the isolation of seven new briarane-type diterpenes, frajunolides E-K (1-7), in addition to 14 known briaranes, praelolide, junceellin, junceellolides A-E, and K, 11a,20a-epoxy-4-deacetoxyjunceelolide D, umbraculolide A, junceellonoid A, and juncins Y, Z, and ZI, as well as ergosterol peroxide. The structures of 1-7 were determined by analysis of HRESIMS and 2D NMR spectroscopic data. Cytotoxicity and in vitro anti-inflammatory activities of compounds 1-7 were also evaluated.

Antiproliferative and hypoglycemic cucurbitane-type glycosides from the fruits of Momordica charantia.

This paper reports that bioassay-guided fractionations of EtOH extract of Momordica charantia fruits led to the isolation of 15 cucurbitane-type triterpene glycosides including 4 new compounds, kuguaosides A-D (1-4), along with 11 known ones, charantoside A (5), momordicosides I (6), F1 (7), F2 (8), K (9), L (10), and U (11), goyaglycosides-b (12) and -d (13), 7β,25-dihydroxycucurbita-5,23(E)-dien-19-al 3-O-β-d-allopyranoside (14), and 25-hydroxy-5β,19-epoxycucurbita-6,23-dien-19-on-3β-ol 3-O-β-d-glucopyranoside (15). Their structures were elucidated on the basis of spectroscopic analyses and chemical methods. This study also established the HPLC-ELSD fingerprinting profile of an antiproliferative fraction of which 11 main peaks were identified. Biological evaluation showed that several isolated cucurbitane-type triterpene glycosides had antiproliferative activities against MCF-7, WiDr, HEp-2, and Doay human tumor cell lines. In addition, compound 14 showed potent hypoglycemic activities by glucose uptake assay.

Synthesis of 1-Substituted Carbazolyl-1,2,3,4-tetrahydro- and Carbazolyl-3,4-dihydro-β-carboline Analogs as Potential Antitumor Agents

A series of 1-substituted carbazolyl-1,2,3,4-tetrahydro- and carbazolyl-3,4-dihydro-β-carboline analogs have been synthesized and evaluated for antitumor activity against human tumor cells including KB, DLD, NCI-H661, Hepa, and HepG2/A2 cell lines. Among these, compounds 2, 6, 7, and 9 exhibited the most potent and selective activity against the tested tumor cells. As for inhibition of topoisomerase II, compounds 1–14 and 18 showed better activity than etoposide. Among them, compounds 3, 4, 7, 9, and 10 exhibited potent activity. The structure and activity relationship (SAR) study revealed correlation between carbon numbers of the side chain and biological activities. The molecular complex with DNA for compound 2 was proposed.

Bioactive Marine Prostanoids from Octocoral Clavularia viridis

Chemical investigation of the nonpolar extract of soft coral Clavularia viridis resulted in isolation of five new prostanoids, designated as claviridic acids A–E (1–5, resp.), in addition to the known clavulones I–III. Their structures were determined on the basis of spectroscopic techniques, especially HR‐ESI‐MS, CD, and 2D‐NMR experiments. The isolated marine prostanoids exhibited potent inhibitory effect on PHA‐induced proliferation of peripheral blood mononuclear cells (PBMC), as well as significant cytotoxic activity against human gastric cancer cells (AGS).

Four New Briarane Diterpenoids from Taiwanese Gorgonian Junceella fragilis

Four new 8-hydroxybriarane diterpenoids, frajunolides P–S (1–4), together with umbraculolide A, juncenolide C, junceellonoid A and juncin R, were isolated from the acetone extract of the gorgonian Junceella fragilis, collected from the southeast coast of Taiwan. Compound 1 contains an unusual pivaloyloxy group at C-2, while 3 is a rare compound having a chlorine atom on the olefinic carbon (C-6). The structures of the isolated compounds were established by extensive spectroscopic analysis, including 1D- and 2D-NMR, as well as HRMS data. Compound 1 was further confirmed by X-ray crystallographic analysis. In the anti-inflammatory test, compounds 1 and 2 exhibited moderate inhibition on superoxide anion generation and elastase release by human neutrophils in response to formylmethionylleucyl-phenylalanine/dihydrocytochalasin B (fMLP/CB).

New Briarane Diterpenoids from the Gorgonian Coral Junceella juncea

Chemical investigation of Junceella juncea has resulted in the isolation of three new briaranes designated juncenolides M–O (1–3). The structures of these compounds were determined by spectroscopic analysis including 2D-NMR (COSY, HMBC and NOESY) and HRMS. Compound 1 is a new chlorinated briarane while compound 3 contains a rare methyl ester at C-16. The anti-inflammatory activities tested on superoxide anion generation and elastase release by human neutrophils in response to FMLP/CB were evaluated.

Frajunolides L–O, Four New 8-Hydroxybriarane Diterpenoids from the Gorgonian Junceella fragilis

Four new 8-hydroxybriarane diterpenoids, frajunolides L–O (1–4), were isolated from the Taiwanese gorgonian Junceella fragilis. The structures of compounds 1–4 were elucidated based on spectroscopic analysis, especially 2D NMR (1H-1H COSY, HSQC, HMBC and NOESY) and HRMS. Compounds 1 and 4 showed weak anti-inflammatory activity as tested by superoxide anion generation and elastase release by human neutrophil in response to fMLP/CB. Compound 3 showed selective inhibition on elastase release in vitro.

Induction of apoptosis in human breast adenocarcinoma cells MCF-7 by monapurpyridine A, a new azaphilone derivative from Monascus purpureus NTU 568.

A new azaphilonidal derivative, monapurpyridine A (MPA), has recently been isolated from the fermented products of Monascus purpureus NTU 568. The structure of MPA was elucidated by nuclear magnetic resonance (1H-NMR, 13C-NMR, COSY, HMQC, and HMBC) and other spectroscopic analyses. Biological evaluation revealed that MPA could induce cell death in human breast adenocarcinoma cells MCF-7, and it has no significant toxicity to normal mammary epithelial cells M10. The MTT assay and flow cytometric analysis were employed to investigate cell viability and cell cycle influenced by MPA. Moreover, we used Western blot and caspase activity assay to demonstrate the activation of caspase-3, -8 and -9 resulted from MPA. All evidence supported that MPA was suitable for developing into a chemotherapeutic or chemopreventive agent against breast cancer.

New Briarane Diterpenoids from Taiwanese Soft Coral Briareum violacea

Ten new briarane diterpenoids, briaviolides A–J (1–10), together with six known briaranes, solenolides A and D, excavatolide A, briaexcavatolide I, 4β-acetoxy-9-deacetystylatulide lactone and 9-deacetylstylatulide lactone, were isolated from the Taiwanese soft coral, Briareum violacea. Their structures were determined on the basis of spectroscopic data (1H- and 13C-NMR, 1H–1H COSY, HSQC, HMBC and NOESY), HR-MS and chemical methods. The absolute configuration of briaviolide A (1) was determined by X-ray crystallographic analysis. Compounds 5, 9 and derivative 11 showed moderate inhibitory activities on superoxide-anion generation and elastase release by human neutrophils in response to N-formyl-methionyl-leucyl-phenylalanine/Cytochalasin B (fMLP/CB).

Arisanschinins A–E, Lignans from Schisandra arisanensis Hay.

Four new oxygenated dibenzocyclooctadiene lignans, arisanschinins A-D ( 1- 4), and a new 1,4-bis(phenyl)-2,3-dimethylbutane lignan, arisanschinin E ( 5), together with 15 known compounds, were isolated from the EtOAc-soluble fraction of the aerial parts of SCHISANDRA ARISANENSIS Hay. The structures of 1- 5 were elucidated on the basis of extensive spectroscopic analyses, including 2D NMR (HMQC, HMBC, and NOESY) experiments. The configurations of the biphenyl and octadiene moieties were deduced from circular dichroism (CD) and NOESY spectra, respectively. Compound 1 showed significant inhibition of α-glucosidase IN VITRO. The radical-scavenging activities of these compounds were evaluated using DPPH.